This invention relates to an air fan, and more particularly to an air fan using a motor as a drive source.
An air fan which has been conventionally known in the art is constructed in such a manner as disclosed in U.S. Pat. No. 4,959,571, U.S. Pat. No. 5,028,216 or the like by way of example. More particularly, the conventional air fan includes a motor support arranged in a casing so as to fixedly mount a stator of a motor thereon and an impeller fixed with respect to a rotor of the motor and having a plurality of blades mounted on an outer periphery of a cylindrical or cup-like member, wherein the motor support and impeller are arranged opposite to each other with a gap being defined therebetween.
Unfortunately, such a conventional air fan fails to a waterproof function. Thus, arrangement of the air fan in an environment in which it is vigorously exposed to rain causes water to intrude into the motor, leading to a failure in operation of the motor and therefore that of the air fan.